Patent AU-2012100192-A4 (AU)
Title: Improved method of reducing fuel consumption of a petrol fuelled four stroke spark ignition engine by altering the engine manifold intake atmosphere by the induction of hot water vapour
Inventor: GREEN KENNETH
IPC: F02B75/10
Filed: 2012-02-23
Granted: 2012-04-05
Abstract: Water injection has been done for a long time with the main aim being power increase. Such water injection is done with ambient temperature water being sprayed into the inlet manifold. It was found that better results were obtained with high pressure spraying which gave a more highly dispersed spray with finer droplets of water. There were some claims of economy. The invention is to create a much finer dispersion of water by heating and causing the water to become steam/hot water vapour. This is achieved by injecting the water into a closed chamber/evaporator which is heated using the exhaust heat of the engine and inducting the produced steam/hot water vapour into the inlet manifold of the engine. The steam/hot water vapour has a much higher vapour pressure than the previously used ambient water spray and displaces a significant proportion of the incoming air as the inlet manifold pressure increases (or vacuum decreases). This causes less air to be drawn into the manifold and the engine management system consequently reduces the fuel being injected into the engine whilst maintaining the air to fuel ratio. The charge of fuel and air has thus been reduced which leads to improved fuel economy. The heat of the steam/hot water vapour induction also heats up and expands the air inside the inlet manifold which reduces the ambient air flow into the inlet manifold even further and results in a further slight reduction in fuel being injected by the engine management system. The injected fuel will be heated up and evaporated better and mixed with the inlet air, effecting better fuel/air charge preparation prior to combustion in the cylinders. It is common practice to run the engines with an excess of fuel to enable cooling of the engine to prevent the production of NOx gases. The extra fuel burns post cylinder in the exhaust manifold which can be seen by the colour of the exhaust pipe. Catalytic converters also need to be used to combust unburnt fuel. The invention provides the introduction of extra water vapour during the induction, compression and ignition strokes which takes over the role of cooling the engine. Using water to cool the engine is obviously a much more economic alternative than using expensive fuel. The mass of water vapour in the cylinder when heated and converted to superheated steam will produce a pressure increase in the cylinder which will increase the power of the engine. The engine can be described as a steam assisted internal combustion engine. If the mass of water exceeds the mass of fuel the engine may also be described as an internal combustion powered steam engine hybrid. The energy to produce the steam/hot water vapour is provided by the exhaust heat of the engine which means that the energy to create the steam/hot water vapour for the induction is not new energy but waste energy of the engine which reduces the energy loss through the exhaust pipe and contributes to engine efficiency. Figure 1 Control Schematic - Staged Manifold Vacuum vaporiser Flow Adjustment block Vapour to manifold Inlet manifold container PUMP12 4D -)4Vacuum line B+Diaphrag Battery